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Anaerobic Digestion of Biowastes- an Alternative Energy Source for Haiti
Reginald Toussaint1 and Ann C. Wilkie2 1School of Natural Resources and Environment
2Advisor, Soil and Water Science Department
Abstract Haiti is facing serious environmental degradation problems making its populace
very vulnerable to natural disasters. Energy consumption patterns of the country
are the most important drivers of this situation. Even today, firewood and
charcoal provide around 66% of the energy consumption on a national scale. This
situation is translated into deforestation, reducing the forest cover of the country
to less than 2%. This study analyzed the current energetic situation of Haiti and
estimated its biogas production potential in order to evaluate the eventual
energetic contribution of anaerobic digestion technology. Amounts of biowastes
generated from different activities were used to assume the biogas potential of
the country. Wood, charcoal, and bagasse respectively represent 55%, 11%, and
4% of the total energy demands of the country. Hydro-energy contributes 5%
while the remainder is provided by imported oil and its derivatives. However,
anaerobic digestion of different kinds of agricultural wastes, human and animal
wastes generated in the country can produce enough methane to meet around
17% of the total energy demand of the country. Two scenarios using 70 and 95%
of available biowastes were evaluated, between 340 and 461 million m3 of
methane can be generated annually from manures, human wastes, and major crop
residues. A typical Haitian farmer can produce enough gas to meet their energy
needs for cooking purposes if all wastes generated on the farm are converted into
biogas. In market places of big cities where large amounts of wastes are
produced, every day, a substantial quantity of methane can be produced through
anaerobic digestion. In conclusion, implementation of anaerobic digestion
technology in Haitian rural sectors can provide sufficient energy to displace a
substantial amount of firewood, thus reducing deforestation and improving air
quality. Furthermore, this technology offers a sanitary solution to manage human
and animal wastes, while producing a mineralized fertilizer for soil management
and sustainable crop production.
Introduction Biomass supplies around 70% of the total energy consumption in Haiti while the
remainder is mostly provided by imported oil and derivatives.
Deforestation accelerated by high energy demand makes the country vulnerable to natural
disasters and drives environmental degradation including soil depletion.
Biowastes are generated from agriculture and livestock, since agriculture is the primary
economic activity of the country.
About 9% and 30% of the population living in urban and rural areas, respectively, practice
open defecation.
Human wastes generated in cities with large populations are not properly managed and
represent an critical threat to public health.
Crop residues, animal manures, and human wastes, can be turned into biogas, which can
be used for cooking or lighting.
Objectives Analyze the current energetic situation of Haiti.
Estimate the biogas production potential of agricultural wastes and manures generated in
the country.
Evaluate the potential contribution of anaerobic technology to the energetic patterns of
Haiti.
Haiti Overview
Discussion Based on our assumed 70 and 95% scenarios, 340 and 461 million m3 of
methane can be generated annually from biowastes, which corresponds to
about 302 to 410 Ktoe, respectively.
Potential biogas production from biowastes can contribute 17% to 23% of
the all energy consumption in Haiti and over 65% of the energy
consumption in rural areas.
Animal manure and human wastes are the best candidates for anaerobic
digestion in Haiti, examined in this study.
Additional biogas can be obtained by increasing the mass of feedstock,
particularly from crop residues.
Anaerobic digestion can be used on small farms or on a larger scale to
produce energy and low cost fertilizer.
Other advantages of anaerobic digestion include prevention of waterborne
diseases, reduction of indoor air pollution and environmental protection.
References Deublein, D. and A. Steinhauser 2008. Biogas from Waste and Renewable Resources. Wiley-VCH Verlag
GmbH and Co., Weinheim, Germany.
IHSI, 2009. Population totale, population de 18 ans et plus, ménages et densites estimes en 2009. Institut
Haitien de Statistiques et d’informatique. Available on http://www.ihsi.ht/pdf/projection.
IBRD/WB, 2007. Haiti: Strategy to alleviate the pressure of fuel demand on national wood fuel resources.
Energy sector Management programs. International Bank for Reconstruction and Development/ Work
bank, Washington, United States.
IPCC. 2006 IPCC Guidelines for national greenhouse gas inventories. Eggleston HS, Buendia L, Miwa K,
editors. Prepared by the National Greenhouse Gas Inventories Programme of the Intergovernmental on
Climate Change.
Lal, R. 2004. World crop residues production and implications of its use as a biofuel. Environment
International 31: 575-584.
UNEP, 2010. The Geo Haiti: State of the Environment. Report 2010. United Nations Environment
Program, Haiti. Available on http://www.pnuma.org/deat1/pdf/GEO_Haiti2010_IN(web)
Wilkie, A.C., 2008. Biomethane from biomass, biowaste and biofuels. In: Bioenergy. p.195-205. J.D. Wall,
C.S. Harwood and A. Demain (eds). American Society for Microbiology Press, Washington, DC.
Methodology • Statistical data for the number of livestock animals and agricultural production was
used to assess the amount of substrates available for anaerobic digestion.
• IPCC guidelines (2006) were used to obtain the amount of volatile solid (VS)
produced per animal per day.
• Amount of crop residue was evaluated by using the range of straw grain ratio
developed by Lal (2004).
• We assume that 70% of the total VS of all wastes is fed to the digester. Further,
Methane production was estimated in a second scenario where 95% of all wastes is
fed to the digester.
• Methane production potential was evaluated using values from IPCC (2006) and
Deublein and Steinhauser (2008).
• Total methane was converted to thousand tons of oil equivalent (Ktoe) and compared
to current energy consumption of the country.
State of the Environment
55%
11% 4%
2%
6%
19%
1% 2%
Energy consumption by fuel type (Ktoe)
Firewood Charcoal Bagasse LPG
Petrol Kerosene Diesel Fuel Oil
47%
15% 3%
16%
19%
Energy consumption per sector (Ktoe)
Rural Households Huban Households
Trade Services Transportation
Industry
Figure 4. Energy consumption (Ktoe/year 2003). Adapted from IBRD/WB(2007). Energy
imported include kerosene, diesel, liquid petroleum gas (LPG), and fuel oil .
Figure 7. Methane potential from animal manure
and human waste. Assumption of 70% of
manure are collected for anaerobic digestion
Figures 3 and 4. Socio-economic indicators of Haiti, adapted from IHSI (2009).
Results
Acknowledgments Thank you to Dr. Ann C. Wilkie and all members of the Bioenergy and Sustainable
Technology Laboratory, especially Ryan E. Graunke and Scott J. Edmundson.
Figure 2. Anaerobic digester
appropriate for Haitian rural areas
Figure 5. Satellite image of the border between
Haiti (left) and the Dominican Republic
(right), showing the intensity of deforestation
within Haiti.
Image credit: NASA
Anaerobic Digestion
Agricultural Wastes Human Wastes Animal Manures
Energy generation Eco-sanitation Bio-fertilizer production Environmental protection Improve indoor air quality Greenhouse Gas Reduction
Figure 1. Benefits of anaerobic digestion of biowastes
Figure 6. Deforestation in Haiti. Every
year between 15 and 20 millions
trees are cut down for the
production of charcoal, cooking and
others purposes (UNEP, 2010).
Figure 8. Methane potential from crop residues.
Assumption of 70% of crop residues are
collected for anaerobic digestion
Conclusions Anaerobic digestion of biowastes can be a sustainable source of energy for Haiti.
Implementation of anaerobic digestion technology in Haiti can not only be
considered a substantial energy source, but can help address issues related to
sanitation, air quality, deforestation, soil depletion and agricultural production.
11.7% 8.6%
27.5%
8.3%
37.4%
0.5% 6.1%
Gross Domestic Product
Non-marketable services
Buildings, public works
Agriculture, breeding and fishing Manufactured products and industries Commerce, restaurants and hotels Electricity and water
Transport and communication
0 10 20 30 40 50 60 70 80 90
100
Met
han
e (
mill
ion
m3)
0
2
4
6
8
10
12
Met
han
e (
mill
ion
m3)
11% 5%
1%
83%
Animal manure
Human waste
Crop wastes
Current energy sources
15%
6%
2%
77%
Figure 9. Percent contribution to total Haitian energy demand by methane from the
anaerobic digestion of biowastes. Assumptions of 70% (left) and 95% (right) of all
biowastes are collected. 0
1
2
3
4
5
0
2
4
6
8
10
12
Total Urban Rural
Pe
op
le/h
ou
seh
old
Nu
mb
er
of
pe
op
le(m
illio
ns)
Land area
Population
Number of people/household
Haiti
Dominican Republic